Donor and recipient plasma follistatin levels are associated with acute GvHD in Blood and Marrow Transplant Clinical Trials Network 0402.

Follistatin is an angiogenic factor elevated in the circulation after allogeneic hematopoietic cell transplantation (HCT). Elevations in follistatin plasma concentrations are associated with the onset of and poor survival after acute GvHD (aGvHD). Using data from the Blood and Marrow Transplant Clinical Trials Network 0402 study (n=247), we sought to further quantify the longitudinal associations between plasma follistatin levels in transplant recipients, as well as baseline HCT donor follistatin levels, and allogeneic HCT outcomes. Higher recipient baseline follistatin levels were predictive of development of aGvHD (P=0.04). High donor follistatin levels were also associated with the incidence of aGvHD (P<0.01). Elevated follistatin levels on day 28 were associated with the onset of grade II-IV aGvHD before day 28, higher 1-year non-relapse mortality (NRM) and lower overall survival. In multivariate analyses, individuals with follistatin levels >1088 pg/mL at day 28 had a 4-fold increased risk for NRM (relative risk (RR)=4.3, 95% confidence interval (CI) 1.9-9.9, P<0.01) and a nearly three-fold increased overall risk for mortality (RR=2.8, 95% CI 1.5-5.2, P<0.01). Given the multiple roles of follistatin in tissue inflammation and repair, and the confirmation that this biomarker is predictive of important HCT outcomes, the pathobiology of these relationships need further study.

Low EGF in myeloablative allotransplantation: association with severe acute GvHD in BMT CTN 0402.

Epidermal growth factor (EGF) is a recently described biomarker of acute GvHD (aGvHD). Whether low plasma EGF prior to hematopoietic cell transplantation (HCT) predisposes to the development of aGvHD, or whether EGF levels fall because of severe aGvHD, is unknown. To evaluate this, we tested plasma samples collected at pre-HCT baseline, day +28 and day +100 during the course of the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0402. We found that baseline EGF plasma concentrations were three-fold lower in HCT recipients compared to donors (24.3 vs 76.0 pg/mL, P<0.01). Ninety-one patients (43%) had a markedly low plasma EGF at pre-HCT baseline, defined as <2.7 pg/mL-an optimal cutpoint associated with development of grade III-IV aGvHD. Patients with these low EGF levels at pre-HCT baseline had a 2.9-fold increased risk of grade III-IV aGvHD by day +100. Patients with low EGF at day +28 after HCT had an increased risk of death (relative risk 2.3, P=0.02) by 1 year due to transplant-related toxicities, especially aGvHD. Our results suggest that very low plasma EGF early in the HCT process may predispose patients to an increased risk of death, potentially due to epithelial damage and limited repair capacity.

L-selectin is dispensable for T regulatory cell function postallogeneic bone marrow transplantation.

In murine models, the adoptive transfer of CD4(+) /CD25(+) regulatory T cells (T(regs) ) inhibited graft-versus-host disease (GvHD). Previous work has indicated a critical role for the adhesion molecule L-selectin (CD62L) in the function of T(regs) in preventing GvHD. Here we examined the capacity of naive wild-type (WT), CD62L(-/-) and ex vivo expanded CD62L(Lo) T(regs) to inhibit acute GvHD. Surprisingly, we found that CD62L(-/-) T(regs) were potent suppressors of GvHD, whereas CD62L(Lo) T(regs) were unable to inhibit disease despite being functionally competent to suppress allo T cell responses in vitro. Concomitant with improved outcomes, WT and CD62L(-/-) T(regs) significantly reduced liver pathology and systemic pro-inflammatory cytokine production, although CD62L(-/-) T(regs) were less effective in reducing lung pathology. While accumulation of CD62L(-/-) T(regs) in GvHD target organs was equivalent to WT T(regs) , CD62L(-/-) T(regs) did not migrate as well as WT T(regs) to peripheral lymph nodes (PLNs) over the first 2 weeks posttransplantation. This work demonstrated that CD62L was dispensable for T(reg) -mediated protection from GvHD.

Sex-based differences in vascular repair with bone marrow cell therapy: relevance of regulatory and Th2-type cytokines.

OBJECTIVES: There are differences in symptoms, risk stratification, and efficacy of pharmacological treatments between men and women with coronary artery disease (CAD). The results of clinical studies of cell therapy in CAD patients are mixed. The relevance of sex to response to cell therapy is unknown. We investigated sex-based differences in response to bone marrow mononuclear cells (BM-MNCs) in atherosclerotic apoliproprotein E-knockout (ApoE -/-) mice. METHODS: Twenty-three male and 27 female ApoE -/- mice fed on a high-fat diet received four intravenous BM-MNC injections (C57BL6/J mice) starting at 14 weeks of age; male or female BM-MNCs were administered. Thirteen male and 20 female atherosclerotic ApoE -/- mice received vehicle. Aortic plaque burden (%), recipient bone marrow progenitor cell profiles (FACS-LSR II, FlowJo) and 22 circulating cytokine panel (LINCOplex) were quantified and analyzed statistically (SSPS, P < or 5). RESULTS: Quantitative and semiquantitative results are presented. Increased G-CSF levels correlated with plaque reduction (r = -.86, P = .0004). G-CSF was clustered with IL-15. CONCLUSIONS: Female but not male BM-MNCs exhibited atheroprotection in male atherosclerotic ApoE -/- mice. Plaque lesions did not attenuate atherosclerosis in female ApoE -/- mice with BM-MNCs of either donor sex. An increase in regulatory and in Th2-type response may be required for atheroprotection. Sex-based differences in vascular repair have implications for cell therapy trials in CAD.

IL-2-based immunotherapy after autologous transplantation for lymphoma and breast cancer induces immune activation and cytokine release: a phase I/II trial.

We determined the safety, immune activating effects, and potential efficacy of i.v. infusion of ex vivo interleukin-2 (IL-2) activated natural killer (NK) cells (part I) or IL-2 boluses (part II) during daily s.c. IL-2 administration following hematopoietic recovery from autologous transplantation. In all, 57 patients with relapsed lymphoma (n=29) or metastatic breast cancer (n=28) were enrolled. In part I of the study, 34 patients were enrolled at three dose levels of ex vivo IL-2-activated NK cells. Lymphaphereses were performed on days 28 and 42 of s.c. IL-2 administration. Following overnight ex vivo IL-2 activation of the pheresis product, the cells were reinfused the following day. In part II, 23 patients were enrolled at three dose levels of supplemental i.v. IL-2 bolus infusions, given on days 28 and 35 during s.c. IL-2 administration. Toxicities were generally mild, and no patient required hospitalization. Lytic function was markedly enhanced for fresh peripheral blood mononuclear cells (PBMNCs) obtained 1 day postinfusion of either IL-2-activated cells or IL-2 boluses. IL-2 boluses transiently increased the levels of IL-6, IFN-gamma, TNF-alpha and IL1-beta, with increases in IL-6 and IFN-gamma being dose dependent. A total of 37 patients (19 patients with lymphoma, 18 with breast cancer) treated with an optimum dose of post-transplant immunotherapy (defined as having received 1.75 x 10(6) IU/m(2)/day of s.c. IL-2 plus at least one of the planned ex vivo IL-2-activated cell infusions/IL-2 boluses) could be matched with controls from the Autologous Blood and Marrow Transplant Registry database. The matched-pairs analysis demonstrated no improvement in disease outcomes of survival and relapse. We conclude that IL-2-activated cells/IL-2 boluses can be safely administered, generate PBMNCs with enhanced cytotoxicity against NK-resistant targets, and increase cytokine levels. With this dose and schedule of administration of IL-2, no improvement in patient disease outcomes was noted. Alternative strategies will be needed to exploit the immunotherapeutic potential of IL-2-activated NK cells.

Preclinical studies targeting normal and leukemic hematopoietic cells with Yttrium-90-labeled anti-CD45 antibody in vitro and in vivo in nude mice.

A study was undertaken to investigate the suitability of using a high affinity (Kd = 1.1 nM) anti-CD45 monoclonal antibody for delivering the high energy beta-particle emitting isotope (90)Y to lymphohematopoietic target cells in vivo. The antibody, AHN-12, recognized the tyrosine phosphatase CD45 expressed on the surface of normal and malignant hematopoietic cells and studies showed that it reacted with both CD45-expressing normal peripheral blood cells and leukemia cells from patients. The antibody was readily labeled with (90)Y using the highly stable chelate 1B4M-DTPA and the radioimmunoconjugate was designated (90)Y-anti-CD45. The agent selectively bound to CD45(+) B cell line Daudi, but not CD45(-) control cells and significantly (p = 0.007) more bound to Daudi tumors growing in athymic nude mice than did a control non-reactive antibody. Moreover, biodistribution data correlated well to an anti-Daudi effect observed against established tumors in nude mice. The effect was dose dependent and irreversible with the best results in mice receiving a single dose of 137 microCi (90)Y-anti-CD45. These mice displayed a significantly (p < 0.0095) better anti-tumor effect than a control (90)Y-labeled antibody and survived over 135 days with no evidence of tumor. Histology studies showed no significant injury to kidney, liver, or small intestine even at 254 microCi, the highest dose tested. Because radiolabeled anti-CD45 antibody can be used to deliver radiation selectively to lymphohematopoietic tissue, these data indicate that this agent may be used to improve treatment of hematopoietic malignancies, particularly leukemia and lymphoma, when combined with hematopoietic stem cell transplantation in a future clinical trial.

Intercellular adhesion molecule-I (ICAM-I, CD54) deficiency segregates the unique pathophysiological requirements for generating idiopathic pneumonia syndrome (IPS) versus graft-versus-host disease following allogeneic murine bone marrow transplantation.

Following allogeneic bone marrow transplantation (alloBMT), idiopathic pneumonia syndrome (IPS) and graft-versus-host disease (GVHD) caused by donor cell alloreactivity remain major obstacles to a successful outcome. Intercellular adhesion molecule-1 (ICAM-1) is an adhesion molecule that is involved in regulating lymphohematopoietic cell migration and facilitating T-cell responses. To determine whether ICAM-1 expression in the host would affect IPS or GVHD tissue injury responses, ICAM-1(-/-) mice were compared with ICAM-1(+/+) controls. ICAM-1(-/-) recipients did not exhibit the manifestations of IPS injury such as an increase in lung weights nor decreased lung function. The influx of T cells, macrophages, and neutrophils was dramatically dampened as was the production of the inflammatory cytokines interferon-gamma and tumor necrosis factor alpha and the chemokines monocyte chemotactic protein 1, macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, and lymphotactin, normally upregulated in the lung during IPS. In contrast, systemic levels of these mediators were unaffected and GVHD-induced lesions in the liver and colon did not differ in severity regardless of ICAM-1 expression. GVHD-mediated mortality was accelerated in ICAM-1(-/-) recipients at doses of allogeneic spleen cells that are otherwise not uniformally lethal. These data implicate ICAM-1 as playing a critical role in the generation of IPS; therefore, ICAM-1 may be a discerning element, segregating IPS from GVHD injury post-alloBMT.

Effects of oxidant stress on inflammation and survival of iNOS knockout mice after marrow transplantation.

In a model of idiopathic pneumonia syndrome after bone marrow transplantation (BMT), injection of allogeneic T cells induces nitric oxide (.NO), and the addition of cyclophosphamide (Cy) generates superoxide (O.) and a tissue-damaging nitrating oxidant. We hypothesized that.NO and O. balance are major determinants of post-BMT survival and inflammation. Inducible nitric oxide synthase (iNOS) deletional mutant mice (-/-) given donor bone marrow and spleen T cells (BMS) exhibited improved survival compared with matched BMS controls. Bronchoalveolar lavage fluids obtained on day 7 post-BMT from iNOS(-/-) BMS mice contained less tumor necrosis factor-alpha and interferon-gamma, indicating that.NO stimulated the production of proinflammatory cytokines. However, despite suppressed inflammation and decreased nitrotyrosine staining, iNOS(-/-) mice given both donor T cells and Cy (BMS + Cy) died earlier than iNOS-sufficient BMS + Cy mice. Alveolar macrophages from iNOS(-/-) BMS + Cy mice did not produce.NO but persisted to generate strong oxidants as assessed by the oxidation of the intracellular fluorescent probe 2',7'-dichlorofluorescin. We concluded that.NO amplifies T cell-dependent inflammation and addition of Cy exacerbates.NO-dependent mortality. However, the lack of.NO during Cy-induced oxidant stress decreases survival of T cell-recipient mice, most likely by generation of.NO-independent toxic oxidants.

CD47 (integrin-associated protein) engagement of dendritic cell and macrophage counterreceptors is required to prevent the clearance of donor lymphohematopoietic cells.

Integrin-associated protein (CD47) is a broadly expressed protein that costimulates T cells, facilitates leukocyte migration, and inhibits macrophage scavenger function. To determine the role of CD47 in regulating alloresponses, CD47(+/+) or CD47(-/-) T cells were infused into irradiated or nonconditioned major histocompatibility complex disparate recipients. Graft-versus-host disease lethality was markedly reduced with CD47(-/-) T cells. Donor CD47(-/-) T cells failed to engraft in immunodeficient allogeneic recipients. CD47(-/-) marrow was unable to reconstitute heavily irradiated allogeneic or congenic immune-deficient CD47(+/+) recipients. These data suggested that CD47(-/-) T cells and marrow cells were cleared by the innate immune system. To address this hypothesis, dye-labeled CD47(-/-) and CD47(+/+) lymphocytes or marrow cells were infused in vivo and clearance was followed. Dye-labeled CD47(-/-) cells were engulfed by splenic dendritic cells and macrophages resulting in the clearance of virtually all CD47(-/-) lymphohematopoietic cells within 1 day after infusion. Host phagocyte-depleted CD47(+/+) recipients partially accepted allogeneic CD47(-/-) T cells. Thus, dendritic cells and macrophages clear lymphohematopoietic cells that have downregulated CD47 density. CD47 expression may be a critical indicator for determining whether lymphohematopoietic cells will survive or be cleared.

Flt3 ligand (FL) treatment of murine donors does not modify graft-versus-host disease (GVHD) but FL treatment of recipients post-bone marrow transplantation accelerates GVHD lethality.

Flt3 ligand (FL) is a hematopoietic cytokine that has been shown to facilitate the expansion of dendritic cells (DCs) and the generation of antitumor immune responses. In addition, the use of FL in mobilizing peripheral blood progenitor cells is being investigated. In the present study, we sought to quantify the influence of FL-treated donor cells on graft-versus-host disease (GVHD). FL treatment resulted in a marked expansion in the absolute number of myeloid- and lymphoid-related DCs and a reduction in the proportion of donor splenic T cells. Irradiated recipients who were given splenocytes from FL-treated donors had reduced GVHD lethality compared with controls due to the infusion of fewer mature T cells. Highly purified T cells from FL-treated donors produced comparable in vitro alloresponses and there was no evidence of a skewing toward T-helper type 1 (interleukin [IL]-2, interferon-gamma) or T-helper type 2 (IL-4, IL-10) cytokine production. The GVHD lethality associated with purified T cells obtained from FL-treated or control donors was comparable. In contrast, FL treatment of recipients resulted in a significant increase in GVHD lethality. Increased lethality was observed even when the infusions of allogeneic T cells and FL were delayed until 3 weeks post-bone marrow transplantation (BMT). Our data indicate that FL treatment of donors does not increase GVHD risk, but treatment of recipients increases GVH lethality even if FL treatment is delayed until later post-BMT.

Human surfactant protein a suppresses T cell-dependent inflammation and attenuates the manifestations of idiopathic pneumonia syndrome in mice.

We have previously shown an association between growth factor-induced upregulation of surfactant protein (SP)-A and suppression of alveolar inflammation in our murine model of donor T cell-dependent lung dysfunction after bone-marrow transplantation, referred to as idiopathic pneumonia syndrome (IPS). We hypothesized that SP-A protects the lung in vivo from IPS injury by downregulation of alveolar inflammation. Human SP-A (100 microg), purified by n-butanol extraction or preparative isoelectric focusing, was transtracheally instilled on Day 4 after BMT during a time of in vivo donor T-cell activation. At 48 h after treatment, immunohistochemical staining of lung sections showed that SP-A did not alter T cell- dependent cellular infiltration. However, macrophages from SP-A-instilled mice were less injured and spontaneously produced less tumor necrosis factor-alpha than did cells from buffer-instilled mice. Although exogenous SP-A did not significantly alter bronchoalveolar lavage fluid (BALF) high levels of total protein (TP), an inverse correlation between BALF SP-A and TP concentrations (r = -0.65; P = 0.02) was observed in SP-A-treated but not in buffer-instilled mice. The only difference between the effects of the two sources of SP-A was that butanol-extracted SP-A, but not isoelectric focusing-purified SP-A, suppressed the interferon-gamma/nitric oxide pathway. We conclude that SP-A downregulates T cell-dependent alveolar inflammation by multiple pathways leading to decreased IPS injury.

Abnormalities of bone marrow mesenchymal cells in multiple myeloma patients.

BACKGROUND: The importance of the bone marrow microenvironment in multiple myeloma is receiving increasing attention. Recent studies have suggested the importance of cytokine production and cell-cell contact by bone marrow stromal cells in the survival of myeloma cells. METHODS: In the current study, the authors examined bone marrow mesenchymal progenitor cell (MPC) cultures derived from eight multiple myeloma patients (mean age, 58 years) and nine normal donors (mean age, 61 years), with emphasis on cell surface antigens, cytokine, and growth factor expression. RESULTS: The authors have found, based on analysis of cellular receptors, growth factors, and cytokine expression, that myeloma MPCs are phenotypically and functionally distinguishable from normal donor MPCs. Immunofluorescence analysis of MPC monolayers shows that myeloma MPC cultures expressed reduced cell surface vascular cell adhesion molecule-1 and fibronectin, in contrast with the strong expression found on normal donor MPCs. Furthermore, a subset of myeloma MPCs strongly express intracellular receptor for hyaluronan-mediated motility, whereas normal MPCs do not. Cytokine expression in bone marrow MPC cultures was examined by reverse transcription-polymerase chain reaction and enzyme linked immunosorbent assay. Bone marrow MPCs constitutively express interleukin (IL)-1beta, IL-6, granulocyte colony-stimulating factor (G-CSF), granulocyte macrophage (GM)-CSF, stem cell factor (SCF), and tumor necrosis factor (TNF)-alpha. In comparison to normal MPCs, multiple myeloma MPCs express increased basal levels of IL-1beta and TNF-alpha. In vitro exposure of MPC cultures to dexamethasone resulted in the down-regulation of IL-6, G-CSF, and GM-CSF in both normal and myeloma MPC cultures. However, dexamethasone treatment significantly increased expression of SCF-1 in myeloma MPCs. CONCLUSIONS: In myeloma, bone marrow stromal cells provide paracrine factors, through cytokine production and cell-cell contact, which play a role in plasma cell growth and survival. The authors' data indicate differences in bone marrow MPCs, which may be biologically relevant to the growth and survival of myeloma plasma cells.

Visualization of immunotoxin-mediated tumor cell death in vivo.

We present a novel methodology to visualize tumor cells directly in a whole mouse. This technique combines immunohistochemistry with whole mouse sectioning. It lets one see the exact distribution of tumor cells throughout an animal and how effectively these cells are eliminated by cancer therapeutics. We used this technique to assess the efficacy of a T cell-specific immunotoxin in a severe combined immunodeficient mouse model of human T-cell leukemia. Severe combined immunodeficient mice were injected with one of two human T-cell acute lymphoblastic leukemia cell lines (Molt 3 and Molt 13) and were either left untreated or were treated with DA7, an immunotoxin specific for the T cell-associated antigen CD7. Mice were sacrificed after tumor cell injection and immunotoxin therapy, whole mouse cross-sections were prepared, and tumor cells in the sections were visualized by immunohistochemistry. No tumor cells were detected in DA7-treated mice injected with Molt 3, consistent with the long-term survival of this group and the sensitivity of Molt 3 to DA7 in vitro. In contrast, DA7 treatment did not visibly eliminate tumor cells in mice challenged with Molt 13, nor did it result in their long-term survival. Furthermore, tumor cells were detected in areas that may have otherwise been overlooked, and their distribution differed from that of mice injected with Molt 13 alone. These analyses indicate that whole mouse sectioning will be a valuable tool for assessing residual disease in the preclinical evaluation of cancer therapeutics.

A phase I clinical, pharmacological, and biological trial of interleukin 6 plus granulocyte-colony stimulating factor after ifosfamide, carboplatin, and etoposide in children with recurrent/refractory solid tumors: enhanced hematological responses but a high incidence of grade III/IV constitutional toxicities.

A Phase I trial was conducted to determine the safety, biological activity, and hematopoietic recovery by the combination of interleukin 6 (IL-6) and granulocyte-colony stimulating factor (G-CSF) after myelosuppressive chemotherapy in children. Patients <22 years of age at diagnosis with either recurrent or refractory solid tumors received ifosfamide 1,800 mg/m2/day x 5 days, carboplatin 400 mg/m2/ day x 2 days, and etoposide 100 mg/m2/day x 5 days, followed by daily s.c. G-CSF (5 microg/kg/day) and IL-6 (2.5, 3.75, or 5.0 microg/kg/day). Pharmacokinetic, proinflammatory mediator levels, hematopoietic colony assays, and cytokine receptor expression studies were performed during course one. Nineteen patients were evaluable for toxicity and received IL-6 at doses of 2.5 (n = 8), 3.75 (n = 5), or 5.0 (n = 6) microg/kg/day. Dose-limiting constitutional toxicity occurred in two of six patients at 5.0 microg/kg/day, two of five patients at 3.75 microg/kg/day, and two of eight patients at 2.5 microg/kg/day. The maximum tolerated dose (MTD) exceeded the lowest dose tested. Because of lack of drug availability, an MTD was not established. The maximum concentration of IL-6 (2.5 microg/kg/day) was 0.799 +/- 1.055 ng/ml (mean +/- SD). During the first course, the median time to absolute neutrophil count > or = 1,000/mm3 and platelets > or = 100,000 mm3 was estimated at 19 and 23 days, respectively. Peripheral blood progenitor cells expressing receptors to IL-3, IL-6, and G-CSF increased significantly over baseline (P < 0.05). After the first dose of IL-6, IFN-gamma levels were abnormal in 13 patients, and IL-1beta levels were abnormal in 10 patients. IL-6 has a high incidence of constitutional toxicity and a lower MTD in children compared with adults. In vivo use of IL-6 in children after chemotherapy remains limited. However, IL-6 may be more optimally investigated in children under ex vivo conditions.

Ligation of 4-1BB (CDw137) regulates graft-versus-host disease, graft-versus-leukemia, and graft rejection in allogeneic bone marrow transplant recipients.

4-1BB is expressed on activated CD4(+) and CD8(+) T cells; its ligand, 4-1BB ligand is expressed on APCs. Despite expression on both T cell subpopulations, 4-1BB has been reported to predominantly affect CD8(+) T cell responses. By quantifying graft-vs-host disease alloresponses in vivo, we demonstrate that both CD4(+) and CD8(+) T cell-mediated alloresponses are regulated by 4-1BB/4-1BB ligand interactions to approximately the same extent. 4-1BB receptor-facilitated CD4(+) T cell-mediated alloresponses were partly CD28 independent. In two distinct marrow graft rejection systems, host CD8(+) and CD4(+) T cells each separately contributed to host anti-donor T cell-mediated allograft rejection. alpha 4-1BB mAb increased the graft-vs-leukemia effect of a suboptimal number of donor splenocytes given later post bone marrow transplantation by bolstering allogeneic responses resulting in leukemia elimination. In summary, 4-1BB ligation is a potent regulator of CD4(+) and CD8(+) T cell-mediated allogeneic responses in vivo. Modifying the ligation of 4-1BB represents a new approach to altering the graft-vs-host disease and graft-vs-leukemia effects of allogeneic T cells post bone marrow transplantation.

Keratinocyte growth factor facilitates alloengraftment and ameliorates graft-versus-host disease in mice by a mechanism independent of repair of conditioning-induced tissue injury.

We have previously shown that pretreatment of mice with keratinocyte growth factor (KGF), an epithelial tissue repair factor, can ameliorate graft-versus-host disease (GVHD) after intensive chemoradiotherapeutic conditioning and allogeneic bone marrow transplantation (BMT). To determine whether this effect was dependent on a KGF-mediated mechanism affecting repair of conditioning-induced epithelial cell injury, we studied GVHD in the absence of conditioning using BALB/c severe combined immune-deficient (SCID) recipients given C57BL/6 T cells. KGF (5 mg/kg per day, subcutaneously) given either before or after T-cell transfer enhanced body weights and extended survival. KGF-treated recipients had elevated serum levels of the Th2 cytokine interleukin 13 (IL-13) on day 6 after T-cell transfer concomitant with reduced levels of the inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interferon gamma (IFN-gamma). A 3-day KGF pretreatment also depressed the secondary in vitro mixed lymphocyte response (MLR) of C57BL/6 splenocytes taken 7 days after in vivo alloimmunization with irradiated BALB/c spleen cells. To determine whether KGF would inhibit host-antidonor-mediated BM rejection, pan-T-cell-depleted BALB/c BM cells were infused into sublethally irradiated C57BL/6 mice and administered KGF either before or before and after BMT. Surprisingly, all KGF schedules tested actually resulted in enhanced alloengraftment. The presence of KGF receptor on donor antihost alloreactive T cells could not be detected by binding studies with radiolabeled KGF, reverse transcriptase-polymerase chain reaction, and Western blotting. Therefore, the mechanism of action of KGF on inhibiting T-cell-mediated immune effects may not be due to a direct effect of KGF on T cells. These studies demonstrate that KGF, by mechanisms independent of repair of conditioning-induced injury, has great potential as an anti-GVHD therapeutic agent with the added benefit of inhibiting the rejection of pan-T-cell-depleted donor BM allografts. (Blood. 2000;96:4350-4356)

Cyclophosphamide prevents systemic keratinocyte growth factor-induced up-regulation of surfactant protein A after allogeneic transplant in mice.

We reported that systemic keratinocyte growth factor (KGF) given before bone marrow transplantation (BMT) prevents allogeneic T cell-dependent lung inflammation assessed on Day 7 post-BMT, but the antiinflammatory effects of KGF were impaired in mice injected with both T cells and conditioning regimen of cyclophosphamide (Cy). Intratracheal KGF is known to stimulate the expression of surfactant protein A (SP-A), an oxidant-sensitive T cell immunomodulator produced by alveolar type II cells. We hypothesized that systemic KGF up-regulates SP-A after allogeneic BMT, and the addition of Cy may interfere with the ability of KGF to enhance SP-A production. The subcutaneous administration of recombinant human KGF (5 mg/kg on Days -6, -5, and -4 pre-BMT) increased SP-A protein and mRNA in allogeneic T cell-recipient irradiated mice measured on Day 7 post-BMT. In contrast, the same KGF treatment in irradiated mice given T cells and Cy failed to up-regulate SP-A mRNA and protein expression. In mixed lymphocyte reaction experiments designed to simulate the in vivo model, the addition of human SP-A (5-50 microg) to alloactivated T cells suppressed the production of interleukin-2 in a dose-dependent fashion. We conclude that the systemic pre-BMT injection of KGF in recipients of allogeneic T cells up-regulates SP-A, which may contribute to the early antiinflammatory effects of KGF. The protective KGF-mediated SP-A production is abolished in mice given alloreactive T cells plus Cy.

T-lymphocyte production of macrophage inflammatory protein-1alpha is critical to the recruitment of CD8(+) T cells to the liver, lung, and spleen during graft-versus-host disease.

To investigate the mechanism by which macrophage inflammatory protein-1alpha (MIP-1alpha) affects graft-versus-host disease (GVHD), the expression and function of MIP-1alpha in 2 murine models of GVHD were evaluated. In irradiated class I and class II disparate recipients, the expression of messenger RNA (mRNA) and protein for MIP-1alpha was significantly increased in GVHD target organs after transfer of allogeneic lymphocytes compared to syngeneic lymphocytes. When lymphocytes unable to make MIP-1alpha were transferred, there was a decrease in the production of MIP-1alpha in the liver, lung, and spleen of bm1 (B6.C-H2(bm1)/By) and bm12 (B6.C-H2(bm12)/KhEg) recipients compared to the transfer of wild-type splenocytes. At day 6 there was a 4-fold decrease in the number of transferred CD8(+) T cells in the lung and approximately a 2-fold decrease in the number of CD8(+) T cells in the liver and spleen in bm1 recipients after transfer of MIP-1alpha-deficient (MIP-1alpha(-/-)) splenocytes compared to wild-type (MIP-1alpha(+/+)) splenocytes. These differences persisted for 13 days after splenocyte transfer. In contrast, the number of donor CD4(+) T cells found in the liver and lung was significantly increased after the transfer of MIP-1alpha(-/-) compared to wild-type splenocytes in bm12 recipients from day 6 through day 10. Thus, the transfer of allogeneic T cells was associated with the enhanced expression of MIP-1alpha in both a class I and class II mismatch setting. However, the increased expression only led to enhanced recruitment of CD8(+), but not CD4(+), donor T cells. Production of MIP-1alpha by donor T cells is important in the occurrence of GVHD and functions in a tissue-dependent fashion.